O-RAN.WG4.CUS.0-v03.00
Technical Specification
O-RAN Fronthaul Working Group
Control, User and Synchronization Plane Specification
Prepared by the O-RAN Alliance. Copyright © 2020 by the O-RAN Alliance.
By using, accessing or downloading any part of this O-RAN specification document, including by copying, saving, distributing,
displaying or preparing derivatives of, you agree to be and are bound to the terms of the O-RAN Adopter License Agreement
contained in Annex ZZZ of this specification. All other rights reserved.
Copyright © 2020 by the O-RAN Alliance.
Your use is subject to the terms of the O-RAN Adopter License Agreement in Annex ZZZ 1
________________________________________________________________________________________________
Copyright © 2020 by the O-RAN Alliance.
Your use is subject to the terms of the O-RAN Adopter License Agreement in Annex ZZZ 2
O-RAN.WG4.CUS.0-v03.00
Revision History
1
Date
Revision
Description
2020.03.13
03.00
Update from comments #43 - #55, accept all changes and fix figure and table numbering
and table of contents as needed.
2020.03.10
02.00.04
Updated using the following CRs: NOK-0021, MAV-0005, ERI-0009, SAM-0016,
SAM-020, SAM-0021, SAM-0022 plus all comments from the comment sheet up to
comment #42
2020.02.28
02.00.03
Updated using the following CRs: ERI-0007, COM-0001, COM-0002 and SAM-0014 …
as well as comments from the comment review sheet.
2020.02.21
02.00.02
Updated using the following CRs: DCM-0002, DCM-0003, NOK-0020, NOK-0026,
NOK-0029, ERI-0004, ETR-0006, SAM-0012, SAM-0013 and two comments received
from Ericsson.
2020.02.14
02.00.01
Updated using the following CRs: NOK-0014, NOK-0017, NOK-0018, NOK-0019,
NOK-0023, NOK-0024, INT-0002, INT-0003, INT-0004, MAV-0001, MAV-0002,
MAV-0003, MAV-0004, ERI-0003, ERI-0006, ETR-0001, ETR-0002, ETR-0003 and
MCS-0001, as well as made minor grammatical corrections.
2019.08.02
02.00
Updated with CR FJT-0001 and NOK-0015 and NOK-0016 and comments #31 - #34
which are the final comments; updated version to v02.00 and created “tc” and clean
versions for WG4 approval.
2019.06.27
01.00.04
Updated with comments #22 - #30 in the review comment sheet as well as based on
discussions at the June 27 meeting. Most changes are related to mandatory/optional
statements and conditions, and in 3.1.3.1.6 regarding endpoint use.
2019.06.20
01.00.03
Updated with changes from Tokyo F2F meeting (see comment sheet), as well as NEC-
0003.
2019.06.10
01.00.02
Accomodates review comments against v01.00.01.
2019.06.02
01.00.01
Updated with NOK-0006, NOK-0007, NOK-0008, NOK-0009, NOK-0010, NOK-0011,
NOK-0012, NOK-0013, ERI-0001, ERI-0002, INT-0001, SAM-0003, SAM-0004, CAB-
0001, CAB-0002 and CAB-0003, which include WI non-ideal fronthaul and several
mandatory / optional modifications, as well as adding Section Extention =6 and =7.
2019.03.11
01.00
Final version 01.00
2
3
________________________________________________________________________________________________
Copyright © 2020 by the O-RAN Alliance.
Your use is subject to the terms of the O-RAN Adopter License Agreement in Annex ZZZ 3
O-RAN.WG4.CUS.0-v03.00
Contents
1
Revision History ................................................................................................................................................. 2
2
Chapter 1 Introductory Material ....................................................................................................................... 10
3
1.1 Scope ............................................................................................................................................................... 10
4
1.2 References........................................................................................................................................................ 10
5
1.2.1 Synchronization-specific Reference Documents ........................................................................................ 11
6
1.3 Definitions and Abbreviations and Conventions ............................................................................................. 12
7
1.3.1 Definitions .................................................................................................................................................. 12
8
1.3.2 Abbreviations ............................................................................................................................................. 14
9
1.3.3 Document Conventions............................................................................................................................................ 14
10
1.3.3.1 Fields and Bitmasks in Messages ......................................................................................................... 14
11
Chapter 2 Architecture & Requirements .......................................................................................................... 16
12
2.1 Functional Split ................................................................................................................................................ 16
13
2.1.1 Selected Split 7-2x (DL) ............................................................................................................................ 17
14
2.1.2 Selected Split 7-2x (UL) ............................................................................................................................ 20
15
2.2 Data Flows ....................................................................................................................................................... 21
16
2.3 Latency Requirements ..................................................................................................................................... 22
17
2.3.1 Timing Parameter Relationships ................................................................................................................ 23
18
2.3.1.1 O-DU Transmission Window ............................................................................................................... 24
19
2.3.2 U-Plane/ C-Plane Timing ........................................................................................................................... 25
20
2.3.3 Computed Latency Methods ...................................................................................................................... 28
21
2.3.3.1 Fronthaul Timing Domain .................................................................................................................... 29
22
2.3.3.2 Defined Transport Method ................................................................................................................... 30
23
2.3.3.3 Measured Transport Method ................................................................................................................ 31
24
2.3.4 Latency Categories for O-DU with dynamic timing advance .................................................................... 32
25
2.3.5 Latency Categories for O-DU with fixed timing advance .......................................................................... 35
26
2.3.6 Non-Delay Managed U-Plane Traffic ........................................................................................................ 36
27
2.4 Reception Window Monitoring ...................................................................................................................... 37
28
Chapter 3 Transport & Protocol Architecture .................................................................................................. 39
29
3.1 Transport Encapsulation Types ........................................................................................................................ 39
30
3.1.1 Ethernet Encapsulation ............................................................................................................................... 39
31
3.1.2 IP/UDP Encapsulation................................................................................................................................ 39
32
3.1.3 Transport Headers ...................................................................................................................................... 40
33
3.1.3.1 eCPRI Transport Header ...................................................................................................................... 40
34
3.1.3.1.1 ecpriVersion (eCPRI protocol revision) .......................................................................................... 40
35
3.1.3.1.2 ecpriReserved (eCPRI reserved) ..................................................................................................... 41
36
3.1.3.1.3 ecpriConcatenation (eCPRI concatenation indicator) ..................................................................... 41
37
3.1.3.1.4 ecpriMessage (eCPRI message type) .............................................................................................. 41
38
3.1.3.1.5 ecpriPayload (eCPRI payload size) ................................................................................................. 41
39
3.1.3.1.6 ecpriRtcid / ecpriPcid (real time control data / IQ data transfer message series identifier) ............ 42
40
3.1.3.1.7 ecpriSeqid (message identifier) ....................................................................................................... 43
41
3.1.3.2 1914.3 Transport Header ...................................................................................................................... 46
42
3.1.3.2.1 RoEsubType (sub type / message type) .......................................................................................... 46
43
3.1.3.2.2 RoEflowID (flow identifier) ........................................................................................................... 47
44
3.1.3.2.3 RoElength (length) .......................................................................................................................... 47
45
3.1.3.2.4 RoEorderInfo (order information)................................................................................................... 47
46
3.2 Protocol Architecture ....................................................................................................................................... 47
47
3.2.1 C-plane ....................................................................................................................................................... 47
48
3.2.2 U-plane ....................................................................................................................................................... 48
49
3.2.3 S-plane ....................................................................................................................................................... 48
50
3.3 Quality of Service ............................................................................................................................................ 48
51
3.4 Data Flow Identification .................................................................................................................................. 49
52
3.5 Fragmentation .................................................................................................................................................. 50
53
3.5.1 Application layer fragmentation ................................................................................................................. 50
54
3.5.2 Radio Transport layer (eCPRI or IEEE-1914.3) fragmentation ................................................................. 50
55
3.5.3 Fragmentation Guideline ............................................................................................................................ 51
56
________________________________________________________________________________________________
Copyright © 2020 by the O-RAN Alliance.
Your use is subject to the terms of the O-RAN Adopter License Agreement in Annex ZZZ 4
O-RAN.WG4.CUS.0-v03.00
Chapter 4 Security ............................................................................................................................................ 52
1
Chapter 5 C-plane Protocol .............................................................................................................................. 53
2
5.1 General ............................................................................................................................................................. 53
3
5.2 Function ........................................................................................................................................................... 53
4
5.2.1 C-Plane Transport ...................................................................................................................................... 53
5
5.3 Elementary Procedures .................................................................................................................................... 53
6
5.3.1 Scheduling and Beamforming Commands Transfer procedure .................................................................. 53
7
5.3.2 Mixed Numerology and PRACH Handling ............................................................................................... 54
8
5.3.3 DL Precoding configuration parameters and indications ........................................................................... 57
9
5.3.4 LAA Commands Transfer procedure ......................................................................................................... 59
10
5.3.4.1 LBT procedure overview ...................................................................................................................... 59
11
5.3.4.2 Definitions ............................................................................................................................................ 60
12
5.3.4.3 General Guidelines for the LAA-procedure ......................................................................................... 61
13
5.3.4.3.1 PDSCH Transmission ..................................................................................................................... 61
14
5.3.4.3.2 DRS Transmission .......................................................................................................................... 62
15
5.3.4.3.3 Congestion Window Information Transmission ............................................................................. 62
16
5.3.5 Symbol Numbering and Duration .............................................................................................................. 62
17
5.3.6 Dynamic Spectrum Sharing (DSS) ............................................................................................................. 63
18
5.3.6.1 Dynamic Spectrum Sharing (DSS) via Dedicated Endpoints ............................................................... 63
19
5.3.6.2 Dynamic Spectrum Sharing (DSS) via Section Extension =9 for DSS ................................................ 63
20
5.4 Elements for the C-plane Protocol ................................................................................................................... 63
21
5.4.1 General ....................................................................................................................................................... 63
22
5.4.1.1 Section Extensions ................................................................................................................................ 64
23
5.4.2 Scheduling and Beamforming Commands ................................................................................................. 64
24
5.4.3 Coding of Information Elements – Transport Layer .................................................................................. 75
25
5.4.4 Coding of Information Elements – Application Layer, Common .............................................................. 75
26
5.4.4.1 dataDirection (data direction (gNB Tx/Rx)) ......................................................................................... 75
27
5.4.4.2 payloadVersion (payload version) ........................................................................................................ 75
28
5.4.4.3 filterIndex (filter index) ........................................................................................................................ 75
29
5.4.4.4 frameId (frame identifier) ..................................................................................................................... 76
30
5.4.4.5 subframeId (subframe identifier) .......................................................................................................... 76
31
5.4.4.6 slotId (slot identifier) ............................................................................................................................ 77
32
5.4.4.7 startSymbolid (start symbol identifier) ................................................................................................. 77
33
5.4.4.8 numberOfsections (number of sections) ............................................................................................... 77
34
5.4.4.9 sectionType (section type) .................................................................................................................... 77
35
5.4.4.10 udCompHdr (user data compression header) ........................................................................................ 77
36
5.4.4.11 numberOfUEs (number Of UEs) .......................................................................................................... 78
37
5.4.4.12 timeOffset (time offset) ........................................................................................................................ 78
38
5.4.4.13 frameStructure (frame structure) .......................................................................................................... 78
39
5.4.4.14 cpLength (cyclic prefix length) ............................................................................................................ 79
40
5.4.5 Coding of Information Elements – Application Layer, Sections ............................................................... 79
41
5.4.5.1 sectionId (section identifier) ................................................................................................................. 79
42
5.4.5.2 rb (resource block indicator) ................................................................................................................. 80
43
5.4.5.3 symInc (symbol number increment command) .................................................................................... 80
44
5.4.5.4 startPrbc (starting PRB of data section description) ............................................................................. 81
45
5.4.5.5 reMask (resource element mask) .......................................................................................................... 81
46
5.4.5.6 numPrbc (number of contiguous PRBs per data section description)................................................... 81
47
5.4.5.7 numSymbol (number of symbols) ........................................................................................................ 82
48
5.4.5.8 ef (extension flag) ................................................................................................................................. 82
49
5.4.5.9 beamId (beam identifier) ...................................................................................................................... 82
50
5.4.5.10 ueId (UE identifier) .............................................................................................................................. 83
51
5.4.5.11 freqOffset (frequency offset) ................................................................................................................ 83
52
5.4.5.12 regularizationFactor (regularization Factor) ......................................................................................... 83
53
5.4.5.13 ciIsample, ciQsample (channel information I and Q values) ................................................................ 83
54
5.4.5.14 laaMsgType (LAA message type) ........................................................................................................ 84
55
5.4.5.15 laaMsgLen (LAA message length) ....................................................................................................... 84
56
5.4.5.16 lbtHandle .............................................................................................................................................. 84
57
5.4.5.17 lbtDeferFactor (listen-before-talk defer factor) .................................................................................... 84
58
5.4.5.18 lbtBackoffCounter (listen-before-talk backoff counter) ....................................................................... 85
59
5.4.5.19 lbtOffset (listen-before-talk offset) ....................................................................................................... 85
60
________________________________________________________________________________________________
Copyright © 2020 by the O-RAN Alliance.
Your use is subject to the terms of the O-RAN Adopter License Agreement in Annex ZZZ 5
O-RAN.WG4.CUS.0-v03.00
5.4.5.20 MCOT (maximum channel occupancy time) ....................................................................................... 85
1
5.4.5.21 lbtMode (LBT Mode) ........................................................................................................................... 85
2
5.4.5.22 lbtPdschRes (LBT PDSCH Result) ...................................................................................................... 85
3
5.4.5.23 sfStatus (subframe status) ..................................................................................................................... 86
4
5.4.5.24 lbtDrsRes (LBT DRS Result) ............................................................................................................... 86
5
5.4.5.25 initialPartialSF (Initial partial SF) ........................................................................................................ 86
6
5.4.5.26 lbtBufErr (LBT Buffer Error) ............................................................................................................... 86
7
5.4.5.27 sfnSf (SFN/SF End) .............................................................................................................................. 86
8
5.4.5.28 lbtCWConfig_H (HARQ Parameters for Congestion Window management) ..................................... 87
9
5.4.5.29 lbtCWConfig_T (TB Parameters for Congestion Window management) ............................................ 87
10
5.4.5.30 lbtTrafficClass (Traffic class priority for Congestion Window management) ..................................... 87
11
5.4.5.31 lbtCWR_Rst (Notification about packet reception successful or not) .................................................. 87
12
5.4.5.32 reserved (reserved for future use) ......................................................................................................... 87
13
5.4.6 Section Extension Commands .................................................................................................................... 88
14
5.4.6.1 extType (extension type) ...................................................................................................................... 89
15
5.4.6.2 ef (extension flag) ................................................................................................................................. 89
16
5.4.6.3 extLen (extension length)................................................................................................................ 89
17
5.4.7 Coding of Information Elements – Application Layer, Section Extensions ............................................... 89
18
5.4.7.1 ExtType=1: Beamforming Weights Extension Type ............................................................................ 89
19
5.4.7.1.1 bfwCompHdr (beamforming weight compression header) ............................................................. 90
20
5.4.7.1.2 bfwCompParam (beamforming weight compression parameter) .................................................... 90
21
5.4.7.1.3 bfwI (beamforming weight in-phase value) .................................................................................... 91
22
5.4.7.1.4 bfwQ (beamforming weight quadrature value) ............................................................................... 91
23
5.4.7.2 ExtType=2: Beamforming Attributes Extension Type ......................................................................... 91
24
5.4.7.2.1 bfaCompHdr (beamforming attributes compression header) .......................................................... 92
25
5.4.7.2.2 bfAzPt (beamforming azimuth pointing parameter) ....................................................................... 92
26
5.4.7.2.3 bfZePt (beamforming zenith pointing parameter) ........................................................................... 93
27
5.4.7.2.4 bfAz3dd (beamforming azimuth beamwidth parameter) ................................................................ 93
28
5.4.7.2.5 bfZe3dd (beamforming zenith beamwidth parameter) .................................................................... 93
29
5.4.7.2.6 bfAzSl (beamforming azimuth sidelobe parameter) ....................................................................... 93
30
5.4.7.2.7 bfZeSl (beamforming zenith sidelobe parameter) ........................................................................... 93
31
5.4.7.2.8 zero-padding ......................................................................................................................................... 94
32
5.4.7.3 ExtType=3: DL Precoding Extension Type.......................................................................................... 94
33
5.4.7.3.1 codebookIndex (precoder codebook used for transmission) ........................................................... 95
34
5.4.7.3.2 layerID (Layer ID for DL transmission) ......................................................................................... 95
35
5.4.7.3.3 txScheme (transmission scheme) .................................................................................................... 95
36
5.4.7.3.4 numLayers (number of layers used for DL transmission) ............................................................... 95
37
5.4.7.3.5 crsReMask (CRS resource element mask) ...................................................................................... 96
38
5.4.7.3.6 crsSymlNum (CRS symbol number indication) .............................................................................. 96
39
5.4.7.3.7 crsShift (crsShift used for DL transmission) ................................................................................... 96
40
5.4.7.3.8 beamIdAP1 (beam id to be used for antenna port 1) ....................................................................... 96
41
5.4.7.3.9 beamIdAP2 (beam id to be used for antenna port 2) ....................................................................... 97
42
5.4.7.3.10 beamIdAP3 (beam id to be used for antenna port 3) ....................................................................... 97
43
5.4.7.4 ExtType=4: Modulation Compression Parameters Extension Type ..................................................... 97
44
5.4.7.4.1 csf (constellation shift flag)............................................................................................................. 97
45
5.4.7.4.2 modCompScaler (modulation compression scaler value) ............................................................... 98
46
5.4.7.5 ExtType=5: Modulation Compression Additional Parameters Extension Type ................................... 98
47
5.4.7.5.1 mcScaleReMask (modulation compression power scale RE mask) ............................................... 99
48
5.4.7.5.2 csf (constellation shift flag)............................................................................................................. 99
49
5.4.7.5.3 mcScaleOffset (scaling value for modulation compression) ........................................................... 99
50
5.4.7.6 ExtType=6: Non-contiguous PRB allocation in time and frequency domain ..................................... 100
51
5.4.7.6.1 rbgSize (resource block group size) .............................................................................................. 100
52
5.4.7.6.2 rbgMask (resource block group bit mask) .................................................................................... 101
53
5.4.7.6.3 symbolMask (symbol bit mask) .................................................................................................... 101
54
5.4.7.7 ExtType=7: eAxC Mask Section Extension ....................................................................................... 102
55
5.4.7.7.1 eAxCmask (eAxC Mask) .............................................................................................................. 102
56
5.4.7.8 ExtType=8: Regularization factor ...................................................................................................... 103
57
5.4.7.8.1 regularizationFactor (regularization Factor) ................................................................................. 103
58
5.4.7.9 ExtType=9: Dynamic Spectrum Sharing parameters ......................................................................... 103
59
5.4.7.9.1 technology (interface name) .......................................................................................................... 104
60
5.4.7.10 ExtType=10: Section description for group configuration of multiple ports ...................................... 104
61
